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/* Copyright (c) 2014 The Chromium OS Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
/* GPIO module for Chrome EC */
#include "common.h"
#include "console.h"
#include "gpio.h"
#include "hooks.h"
#include "registers.h"
#include "task.h"
#include "util.h"
/* Console output macros */
#define CPRINTS(format, args...) cprints(CC_GPIO, format, ## args)
/* For each EXTI bit, record which GPIO entry is using it */
static const struct gpio_info *exti_events[16];
void gpio_pre_init(void)
{
const struct gpio_info *g = gpio_list;
int is_warm = gpio_is_reboot_warm();
int i;
/* Required to configure external IRQ lines (SYSCFG_EXTICRn) */
STM32_RCC_APB2ENR |= 1 << 0;
if (!is_warm)
gpio_enable_clocks();
/* Set all GPIOs to defaults */
for (i = 0; i < GPIO_COUNT; i++, g++) {
int flags = g->flags;
if (flags & GPIO_DEFAULT)
continue;
/*
* If this is a warm reboot, don't set the output levels or
* we'll shut off the AP.
*/
if (is_warm)
flags &= ~(GPIO_LOW | GPIO_HIGH);
/* Set up GPIO based on flags */
gpio_set_flags_by_mask(g->port, g->mask, flags);
}
}
test_mockable int gpio_get_level(enum gpio_signal signal)
{
return !!(STM32_GPIO_IDR(gpio_list[signal].port) &
gpio_list[signal].mask);
}
uint16_t *gpio_get_level_reg(enum gpio_signal signal, uint32_t *mask)
{
*mask = gpio_list[signal].mask;
return (uint16_t *)&STM32_GPIO_IDR(gpio_list[signal].port);
}
void gpio_set_level(enum gpio_signal signal, int value)
{
STM32_GPIO_BSRR(gpio_list[signal].port) =
gpio_list[signal].mask << (value ? 0 : 16);
}
int gpio_enable_interrupt(enum gpio_signal signal)
{
const struct gpio_info *g = gpio_list + signal;
uint32_t bit, group, shift, bank;
/* Fail if not implemented or no interrupt handler */
if (!g->mask || !g->irq_handler)
return EC_ERROR_INVAL;
bit = 31 - __builtin_clz(g->mask);
if ((exti_events[bit]) && (exti_events[bit] != g)) {
CPRINTS("Overriding %s with %s on EXTI%d",
exti_events[bit]->name, g->name, bit);
}
exti_events[bit] = g;
group = bit / 4;
shift = (bit % 4) * 4;
bank = (g->port - STM32_GPIOA_BASE) / 0x400;
#if defined(CHIP_FAMILY_STM32F)
STM32_AFIO_EXTICR(group) = (STM32_AFIO_EXTICR(group) &
~(0xF << shift)) | (bank << shift);
#elif defined(CHIP_FAMILY_STM32F0) || defined(CHIP_FAMILY_STM32L) || \
defined(CHIP_FAMILY_STM32F3)
STM32_SYSCFG_EXTICR(group) = (STM32_SYSCFG_EXTICR(group) &
~(0xF << shift)) | (bank << shift);
#else
#error "Unsupported chip family"
#endif
STM32_EXTI_IMR |= g->mask;
return EC_SUCCESS;
}
/*****************************************************************************/
/* Interrupt handler */
void gpio_interrupt(void)
{
int bit;
const struct gpio_info *g;
/* process only GPIO EXTINTs (EXTINT0..15) not other EXTINTs */
uint32_t pending = STM32_EXTI_PR & 0xFFFF;
STM32_EXTI_PR = pending;
while (pending) {
bit = get_next_bit(&pending);
g = exti_events[bit];
if (g && g->irq_handler)
g->irq_handler(g - gpio_list);
}
}
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